The mission of the UCSF-Gladstone CFAR Virology Core is to provide the most informative and relevant research virology tools to advance CFAR investigators' research programs quickly and efficiently. When conventional methods are warranted, we aim to optimize efficiency and reduce cost. When conventional methods are lacking, we innovate to address unmet needs. In the multidisciplinary translational research setting cultivated by the CFAR, we commonly work with investigators with limited experience in virology, building on their ideas with specialized expertise to generate the highest-quality and timely ideas, designs, and data. In the last grant cycle, the Virology Core contributed to 107 publications, provided mentoring and training to 27 faculty, fellows, or students, and supported 120 independent projects and studies led by 78 investigators. The Core responded to changing needs of CFAR investigators by introducing 17 new assays and services and actively supported CFAR scientific themes including studies of HIV treatment and prevention; latency and eradication; and international studies. Going forward, the Virology Core will continue to address the new challenges in HIV research as identified by OAR and the UCSF-Gladstone CFAR strategic Research Priorities, ensuring that the appropriate virological assays and expertise are available to interested investigators. To fulfill its goals, the Virology Core actively engages CFAR investigators, other core laboratories, NIH- sponsored clinical trial networks and industry partners by: 1) Collaborating directly with CFAR investigators; 2) Providing innovative viral diagnostics with clinically relevant readouts, quality lab services and expert consultation; and 3) Mentoring and training new investigators, staff, and trainees in virologic methods, with the aim of enhancing their research programs and career development.